<!DOCTYPE html>
<html>
<head lang="en">
    <meta charset="UTF-8">
    <title></title>
</head>
<body>
<form method="get">
    网址：<input type="url" name="user_email">
    <br/>
    3位数：<input type="text" name="num" pattern="[0-9]{3}" autofocus>
    <input type="submit">

</form>
</body>
</html>